[Qgis-user] remove 'double' borders in polygon data

[Richard Duivenvoorde]

Hi List,

I think I have a common problem:

I have polygon/area data (in postgis) of let's say countries/cities.

But to visualize it in a WMS with dotted lines, the borders where two 
city polygons overlap/touch you get strange drawing effects because of 
the two dotted lines lying over each other.

Now my colleague pointed to OpenJump where you apparently have: Tools > 
Edit Geometry > Convert > Extract Common Boundary Between Polygons...

But off course this is feasible with QGIS also isn't it ?? ;-)

Anybody an idea to handle this?

If not: Carson, is this a new idea for fTools?

TIA, Regards,

Richard Duivenvoorde